The FCQRONLY system
initialization parameter specifies whether you want CICS to force
all file control requests to run under the CICS QR TCB. This parameter
applies to file control requests that access VSAM RLS files and local
VSAM LSR files. Requests for all other file types always run on the
QR TCB.
- FCQRONLY={YES|NO}
- Valid values are as follows:
- NO
- File Control requests are treated as threadsafe and
are run on an open TCB to avoid unnecessary TCB switching. For CONCURRENCY(REQUIRED)
programs the request runs on an open TCB. For CONCURRENCY(THREADSAFE)
programs the request runs on whatever TCB is being used at the time
of the request.
- YES
- File control requests are treated as non-threadsafe. CICS forces
all file control requests to run under the CICS QR TCB. With all file
requests on the QR TCB, CICS can minimize the amount of locking required
at the expense of additional TCB switches if requests are run on
open TCBs. YES is the default.
For a program defined as
CONCURRENCY(REQUIRED), if the file control request is run under the
CICS QR TCB, CICS switches back to the open TCB before handing control
back to the application program.
For file-owning regions (FORs), choose
an appropriate setting for
FCQRONLY:
- For FORs where the connections to that region are primarily MRO
or ISC connections, these requests run on the QR TCB, and CICS runs
the mirror program primarily on the QR TCB. Specify FCQRONLY=YES so
that all file control requests are processed on the QR TCB. This setting
improves performance by avoiding locking, which is unnecessary when
all file control requests run on the same TCB.
- For FORs where the connections to that region are primarily IPIC
connections, these requests run on open TCBs, and CICS runs the mirror
program on an L8 open TCB whenever possible. Specify FCQRONLY=NO so
that file control requests do not switch to the QR TCB to be processed.
This setting improves performance by multi-threading file control
requests.